JUBA - More than four million South Sudanese, a third of the African country's population, may go hungry at some point in 2013 despite a higher harvest last year, the United Nations said on Friday.

South Sudan's cereal deficit will be 371,000 tonnes, just over one-third of its total cereal requirement, despite an increase in output thanks to good rains and higher sown area, the U.N.'s Food and Agriculture Organisation (FAO) and World Food Program (WFP) said in a report.

Commercial imports will cover some of this year's deficit, but high prices and poor infrastructure will make one million dependent on 224,000 tonnes of food aid planned by the WFP, the report said.

The lack of roads and widespread tribal and rebel violence mean four million will be at risk of not getting enough to eat, it said.

South Sudan, which gained independence from Sudan in 2011, is one of the world's least-developed countries after decades of civil war with Khartoum ended after a peace deal in 2005.

In a country the size of France where only 4.5 percent of the land is cultivated, farming is often hampered by tribal and rebel violence.

South Sudan's ability to import food has also been hit since the government turned off oil production a year ago in a row with Sudan over pipeline fees, depriving the country of what was its virtually only source of income and dollars to buy food abroad.

"South Sudan has tremendous agricultural potential, and the improved harvest estimate is good news, but the country's overall food security situation remains very precarious," WFP country director Chris Nikoi said in a joint statement with FAO.

Over 80 percent of the estimated 11.8 million South Sudanese do not earn wages and are predominantly farmers or tend livestock, according to the World Bank.

But cattle rustling, conflicts between communities and raids by rebel groups continue to hamper farming, the report said. At least 2,600 people have been killed in violence since independence, the U.N. says.

More than 200,000 people have also fled to South Sudan to escape fighting between the army and rebels in the Sudanese states of South Kordofan and Blue Nile, stretching resources in the young republic.

"We must redouble efforts to improve the livelihoods of the poorest and most vulnerable South Sudanese, and ensure they can produce their own food or can afford to buy food to meet their needs, and are more resilient to shocks," Nikoi said.

Reuters